Output sxlector



0Cf l, 1963 c. D. MULLIN ETAL 3,105,876

HEARING CHECKING DEVICE United States Patent O 3,105,876 I-EARINGCEECKING DEVlCE Clayton D. Mullin, St. Paul, and .lohn F. Rose,Minneapolis, Minn., assignors to Maico Electronics, Inc., Minneapolis,Minn., a corporation of Minnesota Filed May 9, 1960, Ser. No. 27,652Claims. (Cl. 179-1) This invention relates to apparatus for checking thehearing capabilities of a person.

There are many instances in which it is desirable to make a rapid, butaccurate, check of the hearing capabilities of a large number of personsin such a manner as to determine if any individuals have pronounceddeciencies in this regard. For instance, it is frequently desirable tomake a determination of the hearing capabilities of all the students ina school.

Various types of audiometers have been known in the past, but many ofsuch audiometers are rather diicult to operate and they are usuallyprescribed for use under cl-osely controlled sound condition, andrequire that the complicated apparatus be a xed or permanentinstallation.

With these considerations in mind, it is to the elimination andimprovement of these `disadvantages in the prior art to which thepresent invention is directed, along with the inclusion therein of othernovel and desirable features.

An object of our invention is to provide a new and improved device ofsimple and inexpensive construction and operation for determininghearing capabilities of a person.

Another object of our invention is to provide novel apparatus forreadily and easily checking the hearing capabilities of a person at aplurality of frequency and intensity levels.

Still another object of our invention is to provide a new and novelhearing check device which is completely embodied in a single unit whichmay be held in a persons hand and easily carried from place-to-place tofacilitate checking of the hearing capabilities of a large number ofpersons at a location where such persons congregate or are likely to befound, such as in schools and the like.

A further object of our invention is to provide an improved apparatusfor quickly checking the hearing capabilities of a number of persons inrapid succession while still maintaining high standards of sterilizationand allowing the apparatus to be adapted for use with ears of varioussizes of various persons.

These and other objects and advantages of our invention will more fullyappear from the following description made in connection with theaccompanying drawings wherein like reference characters refer to thesame parts throughout the several views and in which:

FIG. 1 is a side elevation view of the invention and showing afragmentary sectional View of -a human ear, the hearing capabilities ofwhich are being checked;

FIG. 2 is a rear elevation view of the device which is shown partly insection for clarity of detail.

FIG. 3 is an enlarged side elevation View of the device which is lshownpartly in section for clarity of detail.

FIG. 4 is a section view taken at 4 4 in FIG. 3, and in this viewcertain elements in the background have been removed for clarity;

FIG. 5 is a section view taken at 5-5 in FIG. 3;

FIG. 6 is a detail elevation View showing the inner side of one of theswitching controls;

FlG. 7 is a detail section view of the ear tip detached from the device;and

FIG. 8 is a schematic circuit diagram of the hearing checker.

ice

The hearing checker is indicated in general by numeral 10 and includes a4housing 11 which encloses the selfcontained circuitry and mechanism tobe hereinafter described. Housing 11 includes a tubular and generallycylindrical body or casing 12 which is similar in size and shape to thatof a conventional two-cell flash light, so as to be well adapted to beheld and carried in a persons hand, a head 13, a removable cap 14 and abattery well 15.

The tubular casing 12 encloses a printed circuit board 16 which extendsthroughout the length of the casing and is oriented generally on adiameter of the casing 12. The printed circuit board comprises aportion-of the framework of the device 10 for holding the variousportions of the housing 11 in assembly.

Head 13, which is formed of rigid material and may be of a mouldedplastic construction, is provided with a pair of embedded and ixedlyplaced depending apertured ears 17 extending into the upper end of thetubular casing 12 and normally carrying, in the apertures thereof, aspring p-in 18 which extends across a diameter of the casing 12 andextends through an aperture 19 in the upper portion of the printedcircuit board 16 for releasably holding the head 13 and circuit board inassembly. It should be noted that the pin 19 is readily extractable fromthe aperture 18 and `from the apertured ears 17, and is normallymaintained in the apertured ears by the casing 12.

The lower end of the printed circuit board 16 has a pair of small anglebrackets 20 allixed on opposite sides thereof yas by rivets, and theoutwardly extending flange portions off the angle brackets 20` areprovided with threaded Iapertures 21 into which are threaded screws 22extending through the bottom 15a of the battery well 15 Iand which alsoextend through bights 23a at the ends of coil spring 23 for securing thebattery well 15 and printed circuit board 516 in assembly with thecasing 12 and head 13. It will be noted that the battery well 15 has anout-turned substantially annular flange 15b which bears against thebottom edge of the casing 12 so that 'as the screws 22 are tightened,the battery well and head effectively clamp against opposite ends of thecasing 12. The battery well 15 has a slotted aperture 24 in one sidethereof through which a spring contact 25 extends for engagement withthe sidewall 26 of the battery 27. The other lbattery contact, or tipend 28` bears against the sprin-g contact 23. The spring contact 25 isformed integrally of a bracket portion 25a which is anchored to theprinted `circuit board 16 as by rivets.

The cap 14 is provided with a pair of inwardly extending logs 14a whichare normally carried in the inner ends of the bayonet slots 12a in theend of the casing 112. The flange 15b of the battery well 15 is suitablynotched to permit movement of the lugs 14a into and out 'of the slots12a to permit removing of the cap 14.

The upper end of .the circuit 'board 1-6 extends slightly into the head13 and is maintained in predetermined orientation by spaced lugs 13awhich extend slightly into the upper end of casing 12 to maintain head13 and casing 12 in alignment. Additional lugs 13b on the head 13 alsoextend slightly into the casing 12 for alignment purposes.

'I'he casing 12 and head 13 are maintained in predetermined annularorientation iand are prevented lfrom rotating with respect to each otherby means of the switch cover assembly 28 which is constructed of rigidmoulded mater-i-al and is provided with in-turned `flanges 28a whichhear against the edges 29 of an elongate and broad slot 30 in the casing12. 'I'he slot 30 opens through the upper end of the casing 12 andreceives the switch cover assembly 128 throughout its length. The switchcover assembly has a lower end lip 28fb which lies beneath and abutsagainst the casing 12 at the lower end of slot 30. The in-turned flanges28u project upwardly into a recessed portion 13e 3 of the head `13 andprevent rotation of the head 13 with respect to the casing 12.

The switch cover assembly 28 is provided with a thin sheet covering 31which carries legends to be hereinafter more fully explained. The switchcover assembly is provided with slots 32 and 33 through fwhich extendperipheral portions of generally circular and rotatable switch controlelements 34 and 35 respectively.

The circuit board 16 has a post 36 extending therethrough and 'allixedthereto land rotatably mounting the switch contr-ol elements 34 and 35respectively on opposite sides of board 16. The rotatable switchlcontrol elements 34 and 35 are secured Ion the -post 36 by means ofWashers and retaining rings 37a and 37b respectively. ln FIG. 6 is shownthe inner surface switch control element 35, and an understanding :ofone is sufcien-t for an understanding of both in view of the similarconstruction. The element 35 carries a pai-r of contact elements 38 and39, each of 'which .has a pair of contacts 40 to effect bridging acrossa pair of conductive strips similar to those indicated at 16a on theprinted circuit boa-rd so as to elect a switching function to behereinafter more fully described in connection with the circuit diagramin lFIG. 8. 'Each ofthe switch control elements is provi-ded with -aplurality of recesses 41 and has detents 42 between the recesses and ionthe inner face thereof at a position inwardly from the edge 35a. Each ofthe elements 35 is also provided with recesses 43 and detent 44 nextadjacent the edge 35a. Said recesses and detents cooperate with balls 45and 46 which are mounted at opposite sides of the printed circuit boardadjacent the control elements 34 and 35 and lwhich are cradled inapertures in leaf spring 47 so as to urge the balls into the recessesand thereby maintain .the control elements at predetermined positionsunless manually shifted. The ball 46 cooperates .with recesses 43 anddetent 44 of element 35 to normally hold the control element 35 ineither `one of two positions, but it being understood that the controlelement 35 rmay be rotated so that the ball 46 engages the surfaceportion 35b and thereby permits the control element to be swung to anyof four positions. The ball 445 is located to cooperate with recessesand detents 41 and 42 which are arcuately spaced such as to hold controlelement 341 in any one of four positions.

The rotary control element 35 is further provided with a spring 48mounted lon the arcuate hub 35e beneath Washer 37a. The opposite ends ofspring 48 are engageable with outwardly protruding flange portions 35dand with rigid posts 49 and 50' aixed to the printed circuit board.While the spring engages one of the posts, such as 50, the other end of:the spring enga-ges the corresponding ange 35d, and when the rotatablecontrol element 35 is rotated so that ball 46 moves up on surfaceportion 35b, the spring 48 is flexed and will return the control element35 to a position wherein the ball 46 may set in recess 43 when released.

A bracket 51 mounts a light socket 52 which carries a test light 53. Thelight is disposed adjacent an aperture 13d in the hea-d 13 so as to bevisible from the exterior.

The receiver or speaker 54 is secured in the head 13 by means Aof afitting 55 and at the inner lside of the front wall 13e of the headwhich has a flat outer surface 1:3f. An ear tip-mounting post 56 havinga central passage or aperture 57 extending longitudinally therethroughis integrally mounted with the head 13 and is thereby axed to the head.The passage or aperture 57 is disposed directly in front of the receiver54 so as to transmit sound outwardly therethrough. It will be noted thatthe mounting post 56 has a substantially cylindrical portion 56aadjacent the flat surface 13]c and has an outwardly convergentlytapering outer end portion 56h and an annular rib or bead de-between thecylindrical and tapering surface portions.

The ear tip 58 is removably secured on the post 56 so as to be adaptedto be readily and easily changed so end thereof. The chamber 59 isdefined by an inwardly convergent vtapering conical surface 61 whichextends inwardly la distance slightly less than the distance between rib56e and surface 133 and the surface of chamber 59, at a positioninwardly of surface 61, as at 62, is sub-` stantially cylindricallyformed. It should be pointed out that when the tip 58 is to be removedfrom the post 56, the tip need merely be tipped to an oblique angle withrespect to post 56 whereupon the tip 58 will pop off Ithe post, yet whenthe tip is applied as in FIG. 3, it grips the post and is securely heldin position.

As will become apparent hereinafter in connection with the circuitdiagram, the several positions of the rotatable control elements performthe following functions. When the round dot on the control element '35is adjacent mark 63a the unit is entirely olf and the circuit is openfrom the battery; When adjacent the mark 63h, the test light 53 isoperated, whereupon the operator of the unit will know that the batteryhas or has not sufficient power to operate the sound producing circuitin a manner to produce the desired sound intensity level; at position63e the sound producing circuit is in operation except that the signalsare not being transmitted to the receiver; and at position 63dsound-producing signals are produced and transmitted to the receiverwhereupon the sound is.

produced. It should be pointed out that when the dot of element 35 isdisposed at either of positions 63b or 63d, the control element 35, whenreleased, will be returned by spring 48 to the next adjacent position.

When the control element 34 is oriented so that the round dot on theedge ,thereof is disposed adjacent the mark 64a, the circuit is adjustedto produce sound at the receiver with a pitch of 4000 cycles per secondand an intensity level of 50 decibels; and when the dot is moved to mark64b the circuit is adjusted to produce sound of 4000 cycles and 20 db;when the dot is positioned adjacent mark 64C sound is produced at 2000cycles at 20 db and when the dot is adjacent mark 64d sound is producedat 2000 cycles and 50 db.

It will be understood that ,the printed circuit board. 16 carries anumber of circuit elements, some of which are shown in dotted line inFIG. 3 and indicated in general are tasty meaning battery testing; ottmeaning circuit olf and disconnected from battery; ou meaning circuitprepared for operation, but sound not being produced; and in, soundbeing produced and directed in a persons ear.

The circuit includes a transistor Q1, the base electrode B which isconnected in series through a-rectitier CRI and a resistor R5,stationary in contact L1 and movable contact L to the negative side ofbattery 26. The

base electrode B is also connected to the movable center tap ofpotentiometer R1, the upper end of which is connected to an intermediateprimary winding tap T3 Yof transformer '111, the lower end ofpotentiometer R1 being connected to a resistor R3 which provides ashuntbetween the center tap of R1 and the lower end thereof. The lower end ofpotentiometer R1 is connected through a series resistor R2 to theconnection between diodes CRI and resistor R1. Condenser C1 is connectedin shunt with resistor R2. The lower end of potentiometer R1 is alsoconnected directly to test contact M4 and to in contact N1, out contactN2 and test contact N4. Said last mentioned contacts are also connectedwith one end of resistor R6, the other end of which is connected withthe emitter electrode E of transistor Q1.

The remaining contacts, comprising off contact N4; in Contact M1; outcontact M2; off contact M3; out contact L2; oi contact L3 and testcontact L4 are all open. The wiper contact L of switch 35 is connecteddirectly to a bus B1 Which is directly connected to the intermediate tapP3 of the primary winding in transformer T1. Movable contact M isconnected to bus B1 through series resistor R8 and bulb 53. Movablecontact N is grounded to the case 12 and is connected to the posi-tiveside of battery 26, the negative side of which is connected to the busB1.

The collector electrode C is connected directly to the end P4 of theprimary winding of transformer T1.

The base electrode B is also directly connected to the intermediateprimary winding tap P2 of transformer T1.

The control switch 34 has, schematically, two banks 0f station-arycontacts 11-14 and K1-K4, and corresponding wiper contacts J and K.

The -wiper contact I is connected directly to the end P1 of the primarywinding in transformer T1, and is also connected through a condenser C4to the collector electrode C of the transistor Q1, and is also connectedthrough a trimmer condenser (170 mmfd.-780 mmfd.) to the base electrodeB of the transistor, and is also directly connected to the wiper contactK and to one end S1 of the transformer secondary winding. The contactsJ1 and J2 (2000 cycles) are connected with each other and are connectedthrough a condenser C2 to the collector electrode C of the transistor.The contacts J3 and I4 are connected with each other and are connectedthrough a resistor R7 to the collector electrode C of the transistor.

The coil of receiver 54 is connected at its opposite ends through plug Gand jack H to the bottom end and to the movable center tap,respectively, of potentiometer R12. The lower end of potentiometer R12is also connected to the lower end 52 of the transfoimer secondarywinding. The upper end of potentiometer R12 is connected throughresistor R11 to contact K4, is connected through resistor R to contactK3, is connected through resistor R9 to contact K2 and is directlyconnected to contact K1.

It -should be noted in the drawings that typical values of the circuitcomponents are shown and with the circuit constructed accordinglysatisfactory operation is obtained.

In the test position of control switch 35, the light 53 is connected tothe battery and if llighting is visible to the operator through theaperture 13d, the operator may conclude that the battery is-satisfactory `for use. If no light is visible the battery 26 isexhausted and should be replaced. Likewise the battery should bereplaced if a dull red glow appears momentarily and then disappears.

When the control switch 35 is moved to the tone out position, theinstrument is operating, although sound is not produced at the receiver.The sound may be made audible by moving the control switch 35 to the inposition, whereupon the tone is audible at a frequency and intensitylevel in accordance with the adjustment of control switch 34. Ordinarilythe switch 34 will be adjusted to the proper position so as topredetermine'the tone pitch and the intensity level, prior to themanipulation of control switch 35 to make the sound audible. It will beseen that by adjusting control switch 34, the sound produced will have afrequency olf 2000 or 4000 c.p.s. at either of the intensity levels of20 db or 50 db.

The ear tip 58 should be replaced and cleaned before testing eachsubject or person. An ear tip of suitable size should be applied so as`to produce when inserted into the ear canal, an acoustic seal. Ofcourse care must be taken to prevent the aperture 60 in the ear tip frombei-ng covered or obstructed by the -fleshy areas in the ear.

`It should be noted that the battery 26 may be readily and easilyreplaced by merely removing the cap 14.

It should :further be noted that ready and easy access can be had to allof the components in -the housing 11 to facilitate maintenance andservice if needed., By merely removing the screws 22, the battery -well15 will slip out the bottom end of the casing 12 and the head 13 alongwith the printed circuit board and switch cover assembly 28 will slipoff the top end of the casing, whereupon the switch cover assembly 28 ismerely lifted off and the pin 19 is removed to disassemble the printedcircuit board 16 from the head y13. When the jack H carried on its cardis removed from the plugs on the receiver 54, the head and circuit boardare entirely disassembled.

lIt lwill, of course, 'be understood that various changes may be madei-n the form, detail, -arrangement and proportion of the parts withoutdeparting from the Scope of my invention which consists of the matterdescribed herein and set forth in the appended claims.

What is claimed is:

l. Apparatus for determining hearing capability of a person, comprisingan elongate housing adapted to be carried in a persons hand, an ear tiphaving a domeshaped front end to be inserted slightly into and sealedagainst the periphery of the ear canal, `an ear tip mounting secured tothe housing, the tip and mounting respectively having -interlittingportions defining a releasable snap coupling holding the tip instationary relation ywith. respect to the housing, one of saidinterlitting portions being of resiliently deformable material forreleasably gripping the other intertting portion, the interfittingportion of the tip being integrally formed with the tip andsubstantially smoothly contoured to permit ready and easy cleaning andsterilizing thereof, the mounting and tip having sound-transmittingopenings therethrough, sound-producing means in the housing andtransmitting the same through said openings and including a manuallyoperable control regulating production of sound.

2. Apparatus for determining hearing capability of a person, comprisingan elongate housing adapted to be carried in a persons hand, an ear tipshaped to be inserted into the ear canal and being constructed ofsubstantially rigid but resiliently deformable material, said housinghaving a tipamounting portion including a rigid mounting post projectingoutwardly from the housing and having an annular rib thereon spaced fromthe housing, said tip having a post-receiving :opening and a smoothlycontoured rib-gripping portion with an internal diameter slightlysmaller than the diameter of the rib whereby to detachably secure thetip on the post, the tip and tip-mounting portion havingsound-transmitting openings therethrough, and sound-producing means inthe housing transmitting sound through said openings and including amanually operable control regulating production ot sound.

3. Apparatus for determining hearing capability of a person, comprisingan elongate housing having a head end portion with a generally flatexterior surface on one side thereof, a mounting post on the housing`and projecting outwardly `from said surface, said post having anannular rib thereon spaced from said surface by a first distance, anintegral, one-piece ear tip shaped to be inserted into the ear canal andsaid ear tip having an inner end and a substantially closed outer end,said tipi having a post-receiving opening therein and extending throughsaid inner end, said inner end of the tip abutting against said exteriorsurface of the housing and the wall of the opening tapering convergentlyfrom said inner end to a diameter slightly less than the diameter of therib at a distance 'from said inner end slightly less than said firstdistance whereby the tip is stable on the post and removable therefromfor ready replacement and sterilization, the post and tip having -soundtransmitting openings thered through, sound producing means in thehousing and directing the sound through said openings and including amanually operable control for regulating production of sound.

4. Apparatus for determining hearing capability of a person, comprisingan elongate housing adapted to be carried in a persons hand, -thehousing having a slot at one side thereof and extending longitudinallythereof, ain ear tip secured in stationary relation to one end portionof the housing and shaped to be inserted into the ear canal, the housingand tip having sound-transmitting openings therethrough, sound producingmeans in the housing and including a battery-powered audolrequencysignal generating circuit means including a battery, said circuit meansalso including manually operable control means for regulating theproduction of sound, said control means including a rotary control discoriented longitudinally of the housing and having an arcuatethumb-engaging surface projecting through the slot in the housing to beoperated by a ffore-and-aft rolling action of a persons thumb, framemeans in the housing rotatably mounting the rotary element, andcooperating switching contact means on the frame means and on the rotaryelement and connected with the circuit means for regulating Itheproduction of sound, whereby to prevent a person whose hearing is beingchecked from detecting, apart from the sound being produced, the natureof the regulation of the sound.

5t A selffconltained audible sound-producing apparatus, comprising atubular, open-ended casi-ng having -a slot in one side thereof, anelongate, rigid printed circuit board having circuit means thereon forproducing an audiofrequency signal and having a rotatable controlmounted thereon `for movement to a number of positions for stopping andstarting the signal, said circuit board being the opening in the eartip, a movable cover secured over the battery well, a pair of aperturedears on the receiver housing and projecting into the casing on oppositesides of the circuit board, a mounting pin extending through theapertures of said ear-s and through an aperture in the board, conductivemeans securing said well Ato the correspending end 'of the circuit boardwhereby .to clamp the receiver housing and battery well against oppositeends of the casing and in rigid relation with the circuit board, aspring Contact anchored =by sia-id conductive securing means in the welland engaging the tip end of the battery, a second contact anchored onthe circuit board and projecting into the battery Well land engaging thebattery shell, said conductive means and said second contact beingconnected with the circuit means for supplying power thereto from thebattery.

References Cited in the iile of this patent UNITED STATES PATENTS'2,487,038 Baum Nov. 8, 1949- 2,508,9l8 Hinos May 23, 1950 2,573,438Hathaway et al Oct. 30, 1951 2,924,705 Jones Feb. 9, 1960 3,037,082Tegner et al May 29, 1962

1. APPARATUS FOR DETERMINING HEARING CAPABILITY OF A PERSON, COMPRISINGAN ELONGATE HOUSING ADAPTED TO BE CARRIED IN A PERSON''S HAND, AN EARTIP HAVING A DOMESHAPED FRONT END TO BE INSERTED SLIGHTLY INTO ANDSEALED AGAINST THE PERIPHERY OF THE EAR CANAL, AN EAR TIP MOUNTINGSECURED TO THE HOUSING, THE TIP AND MOUNTING RESPECTIVELY HAVINGINTERFITTING PORTIONS DEFINING A RELEASABLE SNAP COUPLING HOLDING THETIP IN STATIONARY RELATION WITH RESPECT TO THE HOUSING, ONE OF SAIDINTERFITTING PORTIONS BEING OF RESILIENTLY DEFORMABLE MATERIAL FORRELEASABLY GRIPPING THE OTHER INTERFITTING PORTION, THE INTERFITTINGPORTION OF THE TIP BEING INTEGRALLY FORMED WITH THE TIP ANDSUBSTANTIALLY SMOOTHLY CONTOURED TO PERMIT READY AND EASY CLEANING ANDSTERILIZING THEREOF, THE MOUNTING AND TIP HAVING SOUND-TRANSMITTINGOPENINGS THERETHROUGH, SOUND-PRODUCING MEANS IN THE HOUSING ANDTRANSMITTING THE SAME THROUGH SAID OPENINGS AND INCLUDING A MANUALLYOPERABLE CONTROL REGULATING PRODUCTION OF SOUND.